Log HTTP request/response from/to page to a file

The problem that this kind of logging not log body of request/response in readable format . For example I knew that my page made REST calls in JSON format but I fail to find JSON text in generated log file only some HEX format digits .

Is there any way to add human readable body content to this kind of logging ? Or is there any other way to log http header + body ? Proxy solution not possible in my case .

First of all I am aware about https://developer.mozilla.org/en-US/docs/Mozilla/Debugging/HTTP_logging
The problem that this kind of logging not log body of request/response in readable format . For example I knew that my page made REST calls in JSON format but I fail to find JSON text in generated log file only some HEX format digits .
Is there any way to add human readable body content to this kind of logging ? Or is there any other way to log http header + body ? Proxy solution not possible in my case .

提出問題者

Thanks for your answer , but Live HTTP Headers add-on have same disadvantage as Mozilla Debugging - it don't provide body of request/ response . Also it looks like I will need to filter which responses to log and which not . I interested only in REST / AJAX calls from page and don't need to log image / scripts loading .

I still open for suggestion but currently I see only one choice - write my own extension will handle all as I actually need :)

Thanks for your answer , but Live HTTP Headers add-on have same disadvantage as Mozilla Debugging - it don't provide body of request/ response . Also it looks like I will need to filter which responses to log and which not . I interested only in REST / AJAX calls from page and don't need to log image / scripts loading .
I still open for suggestion but currently I see only one choice - write my own extension will handle all as I actually need :)